The present invention relates to a bar code reader for reading a bar code by irradiating the bar code with laser beams and detecting a change in intensity of reflected laser beams, and demodulating the bar code into character data. The present invention relates more particularly to a bar code reader and a scaling device which incorporate a scaling function, and to a scaling method.
As typified by a POS (Point of Sales) system in a distribution sector over the recent years, it has been generalized that the merchandises are managed by bar codes. For instance, according to the POS system in a shop, pieces of data such as categories and sales prices of the goods are coded in a bar code format, and printed or pasted onto the goods. Then, the bar code of the goods is read at a cash register in a payment location, whereby the number of goods sold is added up in real time as well as doing the payment of a charge. This serves for a stock management and a purchase management.
A bar code reader (a scanner device) for reading the bar code on the goods is roughly classified into a fixed type reader used for comparatively small goods formed with the bar codes, and a handy type reader used for comparatively large goods. The fixed type bar code reader thereof is provided with a mechanism (a scanning/converging optical system) for scanning the bar code in a multiplicity of directions by irradiating the bar code with light beams for reading so that an operator is capable of reading the bar code without being so aware of a bar code direction. More specifically, the bar code is scanned in the multiplicity of directions with the laser beams defined as reading irradiation light beams during a scan by one reflection surfaces of a polygon mirror used in combination with fixed reflection mirrors. Then, during such a scan process, the laser beams reflected from the surface of the goods are received, and a demodulation processing circuit (a control circuit) demodulates change-of-intensity data (reflected light data) of the thus received reflected laser beams with a demodulation algorithm for the bar code and extracts data coded into the bar code. Further, the fixed type bar code reader includes a scale function unit together with the scan function unit in order to enable the goods to be sold by weight.
In the prior art bar code reader, a scan/display panel of the scan function unit is provided with a start button (a switch) for shifting the scan function unit to a wake-up state (an operating state) and a sound adjusting button for adjusting a volume or a tone of the sound from a loudspeaker. Further, a scale-oriented display connected to the scale function unit is provided with a zero-adjusting button for making a zero-adjustment of the scale. Accordingly, the operator inevitably operates the button and the switch disposed in different positions on the scan/display panel and the scale-oriented display as the necessity may arise. Such a button operation in combination with the operation of reading the bar codes of a large quantity of goods might lead an increased load on the operator. Moreover, the zero-adjustment of the scale of the scale of the cal function unit is allowed to be done only before placing the goods. This is because if the zero-adjustment is made in a state where the goods remains placed, a weight thereof is displayed in minus when the goods is removed. In this case, the operator needs to re-execute the zero-adjustment after temporarily removing the goods, which might be a factor for increasing the load on the operator. Furthermore, with the construction that the zero-adjustment of the scale of the scan function unit is made only before placing the goods, it is unfeasible to cope with an operational mistake (a deviation in timing) of the operator.
Accordingly, it is a primary object of the present invention to provide a bar code reader and a scaling method which are capable of operating in one location a start button (a switch) for shifting a scan function unit to a wake-up state (an operating state) from a sleep state (non-operating state), a sound adjustment button for adjusting a volume or a tone of a sound from a loudspeaker, and a zero-adjustment button for performing a zero-adjustment of a scale of a scale function unit.
It is another object of the present invention to provide a bar code reader and a scaling method which are capable of integrating a variety of function buttons operable in one location, into one same button.
It is still another object of the present invention to provide a bar code reader, a scaling device and a scaling method which are capable of performing the zero-adjustment of the scale of the scale function unit even in a state where the goods is placed when selling the goods by weight.
It is a further object of the present invention to provide a bar code reader, a scaling device and a scaling method which are capable of preventing an operational mistake and an unfair operation by an operator when selling the goods by weight.
To accomplish the above objects, according to a first aspect of the present invention, a bar code reader comprises a bar code processing unit for generating a bright/dark pattern containing a plurality of bright areas and a plurality of dark areas forming a bar code by optically scanning a bar code forming surface of an object, converting the bright/dark pattern into plural categories of module values indicating widths of the respective bright areas and widths of the respective dark areas, and demodulating the bar code into character data, a scaling unit for creating scale data by scaling a weight of the object, a zero-adjustment control unit for working a weight scaling function of the scaling unit to perform zero-setting in response to a request for initializing the scaling unit, and a weight change judging unit for judging at least one of an increment change and a decrement change from zero in weight on the basis of the scale data created by the scaling unit, and outputting a corresponding piece of scale data when in the increment change and an absolute value of a corresponding piece of scale data when in the decrement change.
The bar code reader taking this construction may further comprise an automatic zero-adjustment control unit for forcibly working the weight scaling function of the scaling unit to perform the zero-setting when the weight change judging unit judges the decrement change and outputs the absolute value of the scale data.
Further, a box body of the bar code reader incorporates a first switch element for enabling an operator to input the request for initializing the scaling unit, and a second switch element for enabling the operator to start up another processing function containing control for changing any one of a volume and a tone of a confirmation sound emitted from a loudspeaker when the bar code processing unit reads the bar code.
The bar code reader of the present invention may take such a configuration that the first switch unit and the second switch unit are integrated into one same switch unit.
In this configuration, the bar code reader may further comprise a selecting unit for starting up a corresponding processing function when any one of the first and second switch elements is operated corresponding to the number of operations of the integrated switch element.
Moreover, the bar code reader may further comprise a selecting unit for starting up a corresponding processing function when any one of the first and second switch elements is operated corresponding to an operation continuous time of the integrated switch element.
According to a second aspect of the present invention, a scaling device comprises a unit for comparing a weight of an object at a first point of time with a weight of the object at a second point of time posterior to the first point of time, and a unit for outputting, when there occurs a decrement change in weight as a result of the comparison, scale data with plus and minus of the change being reversed.
According to a third aspect of the present invention, a scaling device comprises a unit for comparing a weight of an object at a first point of time with a weight of the object at a second point of time posterior to the first point of time, and a unit for outputting, when there occurs a decrement change in weight as a result of the comparison, scale data corresponding to an absolute value of the change.
According to a fourth aspect of the present invention, a scaling device comprises a unit for comparing a weight of an object at a first point of time with a weight of the object at a second point of time posterior to the first point of time, and a unit for automatically setting, when there occurs a decrement change in weight as a result of the comparison, the weight of the object at the second point of time to zero.
According to a fifth aspect of the present invention, a scaling method comprises a step of creating scale data by scaling a weight of an object by a zero-set scaling device, a step of judging at least one of an increment change and a decrement change from zero in weight on the basis of the created scale data, a step of outputting a corresponding piece of scale data when in the increment change, and a step of outputting an absolute value of a corresponding piece of scale data when in the decrement change.
This scaling method may further comprise a step of selecting a start-up of a processing function of making the scaling device perform zero-setting, and a start-up of another processing function containing control for changing any one of a volume and a tone of a confirmation sound emitted from a loudspeaker when reading the bar code, corresponding to a difference between operation methods of one same switch unit.
According to the bar code reader, the scaling device and the scaling method of the present invention which take the above configurations, it is possible to prevent a payment from not being normally made due to an operational mistake and an unfair operation by an operator such as a case of selling the goods by weight.
Further, the zero-adjustment of the scale of the scale function unit can be carried out even in a state where the goods remains placed such as the case of selling the goods by weight, and hence a load on the operation can be reduced.
Moreover, it is feasible to operate in one location switch elements such as a start button (a switch) for shifting a scan function unit to a wake-up state (an operating state) from a sleep state (non-operating state), a sound adjustment button for adjusting a volume or a tone of a sound from a loudspeaker, and a zero-adjustment button for performing a zero-adjustment of the scaling unite, whereby the load on the operator can be decreased.
In addition, the variety of function buttons operable in one location can be integrated into one same switch element, and the load on the operator can be further reduced.